Numerical simulation of thermal distribution in quasi-heatcapacity fiber lasers

Abstract

In this paper, a quasi-heat-capacity fiber laser is designed, which uses a heat sink to store heat during the operation time, and uses a low-energy cooling system to cool down slowly. Compared with conventional water-cooled or air-cooled fiber lasers, this quasi-heat-capacity fiber laser has a compact structure with low-energy consumption, which might be useful for platforms that have strict requirements for volume, weight and energy consumption. By using the finite element analysis (FEA) method, a detailed quantitative thermal analysis of the proposed quasi-heat-capacity fiber laser is investigated. The laser heat source consists of two pumping laser diodes (LDs), gain fibers, and an electronic power source. During operation, the heat is stored only through an aluminum heat sink with a limited mass of 5 kg. The lasing- on-time of the laser is defined as the time when the temperature of LD bottom plate increases from 20 °C to 30 °C for the first time in a certain period of working time, which is the best working temperature range of the wavelength stabilized LDs. Numerical simulation results show that when the fiber laser works in heat capacity mode, the lasing-on-time can be effectively improved.